Characterization of an ester-based core-multishell (CMS) nanocarrier for the topical application at the oral mucosa

Objectives

Topical drug administration is commonly applied to control oral inflammation. However, it requires sufficient drug adherence and a high degree of bioavailability. Here, we tested the hypothesis whether an ester-based core-multishell (CMS) nanocarrier is a suitable nontoxic drug-delivery system that penetrates efficiently to oral mucosal tissues, and thereby, increase the bioavailability of topically applied drugs.

Material and methods

To evaluate adhesion and penetration, the fluorescence-labeled CMS 10-E-15-350 nanocarrier was applied to ex vivo porcine masticatory and lining mucosa in a Franz cell diffusion assay and to an in vitro 3D model. In gingival epithelial cells, potential cytotoxicity and proliferative effects of the nanocarrier were determined by MTT and sulphorhodamine B assays, respectively. Transepithelial electrical resistance (TEER) was measured in presence and absence of CMS 10-E-15-350 using an Endohm-12 chamber and a volt-ohm-meter. Cellular nanocarrier uptake was analyzed by laser scanning microscopy. Inflammatory responses were determined by monitoring pro-inflammatory cytokines using real-time PCR and ELISA.

Results

CMS nanocarrier adhered to mucosal tissues within 5 min in an in vitro model and in ex vivo porcine tissues. The CMS nanocarrier exhibited no cytotoxic effects and induced no inflammatory responses. Furthermore, the physical barrier expressed by the TEER remained unaffected by the nanocarrier.

Conclusions

CMS 10-E-15-350 adhered to the oral mucosa and adhesion increased over time which is a prerequisite for an efficient drug release. Since TEER is unaffected, CMS nanocarrier may enter the oral mucosa transcellularly.

Clinical relevance

Nanocarrier technology is a novel and innovative approach for efficient topical drug delivery at the oral mucosa.

     

Generation of full‐thickness skin equivalents using hair follicle‐derived primary human keratinocytes and fibroblasts

Skin equivalents are increasingly used as human‐based test systems for basic and preclinical research. Most of the established skin equivalents are composed of primary keratinocytes and fibroblasts, isolated either from excised human skin or juvenile foreskin following circumcisions. Although the potential of hair follicle‐derived cells for the generation of skin equivalents has been shown, this approach normally requires microdissections from the scalp for which there is limited subject compliance or ethical approval. In the present study, we report a novel method to isolate and cultivate keratinocytes and fibroblasts from plucked hair follicles that were then used to generate skin equivalents. The procedure is non‐invasive, inflicts little‐pain, and may allow easy access to patient‐derived cells without taking punch biopsies. Overall, minor differences in morphology, ultrastructure, expression of important structural proteins, or barrier function were observed between skin equivalents generated from hair follicle‐derived or interfollicular keratinocytes and fibroblasts. Interestingly, improved basal lamina formation was seen in the hair follicle‐derived skin equivalents. The presented method here allows easy and non‐invasive access to keratinocytes and fibroblasts from plucked hair follicles that may be useful particularly for the generation of skin disease equivalents.